Two new studies prove that if HIV-negative people take anti-HIV medication they're substantially less likely to contract the virus that causes AIDS. Don't get too excited, gays: It's only proven for heteros.

In one study by the CDC involving 1,200 sexually active people in Botswana, half were given the drug Truvada, which is used to treat HIV, and half were given a placebo. Only four of the people given Truvada contracted the virus but 19 people on the placebo were infected. That shows a 78% decrease in the risk of contracting the virus if you're on the medication. Another study by the University of Washington (and paid for by the Bill & Melinda Gates Foundation) involved 5,000 heterosexual couples in Kenya and Uganda where one partner was HIV-positive and one was HIV-negative. Researchers did a similar experiment, giving the HIV-negative partners Truvada, Viread (another pill used to treat HIV), or the dreaded placebo. There were only 13 infections on Truvada, 18 on Viread, and 47 who succumbed to the curse of the placebo. Those are encouraging results, but, man, science can be so freaking cruel!